I will check your kit data log during manufacturing operation to check if I am finding anything strange. This wmay take a couple of days.
==> Have you check whether a factory reset of K64 and KW41 is helping ?
See user guide sections 4.1.1. and 4.1.2.
To further support my investigation, did you try using a third party BLE application (like BLE Scanner)
Using this third party app you will be able to check whether the issue is rather coming from the kit itself or the app
You will see an 'Atmosphere Project' entity to which you can connect (likely) and then see whether you can access the services.
Please give a try and let me know what is the outcome.
Once connected, to BLE scanner app, the BLE letter on the kit should turn blue.
In case BLE Scanner does not allow you to connect, it would mean the pb comes from the kit and it will help me focusing on the potential root causes.